As communications products tend to be increasingly compact, integrated, and fast, pluggable transmission apparatuses are increasingly popular in communications apparatuses. For example, XFP opto-electronic modules (10 Gigabit Small Form Factor Pluggable Modules, 10 gigabit small form factor pluggable optical modules) are widely used in the optical communications field following SFP opto-electronic modules (small form-factor pluggable opto-electronic modules), and the MSA (Multisource Agreement) protocol for the XFP modules is used to define the XFP modules. As stipulated by the protocol, an XFP module needs to be unlocked using a self-contained unlocking apparatus so that the XFP module can smoothly disengage from the shell of the system mother board. However, in the prior art, the unlocking apparatus is incapable of automatically resetting after the apparatus is unlocked.